The present invention relates to a high speed searching device utilizing an A/C head (Audio and Control head) of a video cassette tape recorder (hereinafter, referred to as VCR), and more particularly to a high speed searching device utilizing the rotary A/C head which renders to turn the A/C head itself in a state where the tape is not drawn out from tape cassette and contacting the tape during high speed running so that high speed searching function can be carried out without giving any over-strain to the tape.
In a conventional VCR that has been generally used various kinds of high speed searching devices have been known which searches a particular signal recorded on the tape while running the tape with high speed and verifying the location of desired picture and then being used to play back at play back mode. In most of these conventional devices, such system which utilizes mainly tape guide means and renders the tape to be half loading to the A/C head and then carries out the high speed searching function by the high speed running of tape, is widely used.
That is, exemplifying one of such high speed searching device of a conventional VCR which is well known, as shown in FIG. 5, an A/C head 2 is provided fixedly at one side of a head drum 1, in front of the head drum 1, there are respectively provided a cam gear 3 formed with a cam groove 3a and a connecting plate 4 which has cam pin 4a to be inserted in the cam groove 3a of said cam gear 3 and being moved to right and left in response to the normal or reverse rotation of the cam gear 3, one end of an interlocking lever 5 is, inserted in an operating pin 4b mounted at the other side of the connecting plate 4, i.e., at an opposite side of the position of the cam pin 4a, and one end of a turning lever 6 provided with guide post 6a is contacted to another end of the interlocking lever 5.
Therefore, according to the conventional high speed searching device constructed as above, the operation is such that when a driving motor (not shown) is driven and the cam gear 3 is turned clockwise, the cam pin 4a of connecting plate 4 is moved in a rightward direction. Thus, since the connecting plate 4 and operating pin 4b are moved in the same direction, the interlocking lever 5 connected to the operating pin 4b and the turning lever 6 interlocked in the this are turned to arrow direction as much as a predetermined angle and draws out the tape from the middle pocket C1 of tape cassette C by guide post 6a mounted at its front end, in a state of half loading so as the drawn tape T is being contacted to the A/C head 2, the tape T is rendered to high speed running (FF/REW) so that the desired high speed searching function is carried out.
However, in the conventional device of this system, since two levers 5 and 6 for drawing and contacting the tape T to the A/C head 2 fixed to base plate are required, the structure of the whole device becomes complicated, and the tape T is half loaded by the guide post 6a of the turning lever 6, accordingly such a case that the tape T being inserted between the guide post 6a and A/C head 2 owing to either the perpendicularity of the guide post 6a or tilt or azimuth angle of A/C head 2 has often arisen and becoming to cause the damage of tape T, since the ratio between the interlocking lever 5 and turning lever 6 is too much, it is difficult to set correctly the position of the guide post 6a. Furthermore, the running path of tape at the time of high speed searching is carried out by supply reel 7-guide 9a-guide post 6a-tape guide 9c-guide 9b-take-up reel 8, and in this half loading state, the frictional portion contacted with tape T is relatively increased, whereas since the tape T runs with high speed, becoming to cause the damage of tape T and reduction of searching speed, and since the running tape T is constantly wrapping to one side of circumference of head drum 1, there has been the disadvantage and problem that the damaging factor of head drum 1 by the surface friction can not be excluded.